Field
Exemplary embodiments of the present invention relate to an organic material deposition device capable of sensing a deposition amount of an organic material deposited in a vacuum chamber, and an organic light emitting diode (OLED) display manufactured thereby.
Discussion of the Background
A quartz crystal microbalance (QCM) sensor is commonly used for sensing a deposition amount of an organic material deposited in a vacuum chamber of an organic material deposition device. The QCM sensor uses a bulk acoustic wave (BAW) method to sense the deposition amount of the organic material by applying a frequency in a range of 2 to 6 MHz.
As the organic material is being deposited, the temperature inside the vacuum chamber increases, thereby deteriorating measurement reliability as a result of the increasing temperature. For example, the available temperature range of the QCM sensor is from 0 to 70° C. As the organic material is accumulated, a temperature increasing effect is generated on a film surface of the QCM sensor, and a condensed film is formed thereon as a result.
Such vacuum deposition may cause a crystal electrode to be deformed and generally stressed, resulting in frequency deviation. When a very high stress is applied to the electrode, a coated organic material condensed film produces a multi-vibration or a couple-vibration. Accordingly, an instantaneous error (e.g., ±100 or 200 Å) may be generated.
As a result, fine adjustment needs to be performed on a contact gap when the QCM sensor is replaced. Therefore, a sensing dispersion (10 to 50 Å) may be varied according to the adjustment on the contact gap of the QCM sensor.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and, therefore, it may contain information that does not constitute prior art.